Tegra: enable -nostdlib flag

This patch enables the '-nostdlib' flag to instruct the compiler
to not use the standard system libraries and startup files.

Change-Id: Ibf34856f7579ed686280cee19c35d08448cf921c
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>

plat/nvidia/tegra/platform.mk

@@ -40,5 +40,5 @@ include ${SOC_DIR}/platform_${TARGET_SOC}.mk
 # modify BUILD_PLAT to point to SoC specific build directory
 BUILD_PLAT	:=	${BUILD_BASE}/${PLAT}/${TARGET_SOC}/${BUILD_TYPE}
 
-# enable signed comparison checks
-TF_CFLAGS	+= -Wsign-compare
+# platform cflags (enable signed comparisons, disable stdlib)
+TF_CFLAGS	+= -Wsign-compare -nostdlib